Filename | Description --------------------|---------------------------------------------------------------------------------------------------------------------------- banlist.dat | stores the IPs/Subnets of banned nodes bitcoin.conf | contains configuration settings for bitcoind or bitcoin-qt bitcoind.pid | stores the process id of bitcoind while running blocks/blk000??.dat | block data (custom, 128 MiB per file); since 0.8.0 blocks/rev000??.dat | block undo data (custom); since 0.8.0 (format changed since pre-0.8) blocks/index/* | block index (LevelDB); since 0.8.0 chainstate/* | blockchain state database (LevelDB); since 0.8.0 database/* | BDB database environment; only used for wallet since 0.8.0; moved to wallets/ directory on new installs since 0.16.0 db.log | wallet database log file; moved to wallets/ directory on new installs since 0.16.0 debug.log | contains debug information and general logging generated by bitcoind or bitcoin-qt fee_estimates.dat | stores statistics used to estimate minimum transaction fees and priorities required for confirmation; since 0.10.0 indexes/txindex/* | optional transaction index database (LevelDB); since 0.17.0 mempool.dat | dump of the mempool's transactions; since 0.14.0 peers.dat | peer IP address database (custom format); since 0.7.0 wallet.dat | personal wallet (BDB) with keys and transactions; moved to wallets/ directory on new installs since 0.16.0 wallets/database/* | BDB database environment; used for wallets since 0.16.0 wallets/db.log | wallet database log file; since 0.16.0 wallets/wallet.dat | personal wallet (BDB) with keys and transactions; since 0.16.0 .cookie | session RPC authentication cookie (written at start when cookie authentication is used, deleted on shutdown): since 0.12.0 onion_private_key | cached Tor hidden service private key for `-listenonion`: since 0.12.0 guisettings.ini.bak | backup of former GUI settings after `-resetguisettings` is used Only used in pre-0.8.0 --------------------- * blktree/*; block chain index (LevelDB); since pre-0.8, replaced by blocks/index/* in 0.8.0 * coins/*; unspent transaction output database (LevelDB); since pre-0.8, replaced by chainstate/* in 0.8.0 Only used before 0.8.0 --------------------- * blkindex.dat: block chain index database (BDB); replaced by {chainstate/*,blocks/index/*,blocks/rev000??.dat} in 0.8.0 * blk000?.dat: block data (custom, 2 GiB per file); replaced by blocks/blk000??.dat in 0.8.0 Only used before 0.7.0 --------------------- * addr.dat: peer IP address database (BDB); replaced by peers.dat in 0.7.0